Conveyor device, and article testing unit having the same

ABSTRACT

A weighing conveyor having an increased weighing accuracy. This conveyor includes a conveyor apparatus  3  for transporting an article X to be weighed, a load detector  5  for detecting the weight of the article X to be weighed, and a housing  7  for accommodating the load detector  5 , in which a fixed end  5   b  of the load detector is connected with the housing  7  and a free end  5   c  thereof is connected with a support member  120  for supporting the conveyor apparatus  3 , and the support member  120  protrudes outwardly of the housing  7  from a bottom surface thereof.

FIELD OF THE INVENTION

[0001] The present invention relates to a conveyor apparatus and acommodity inspecting equipment equipped with such conveyor apparatus.

BACKGROUND ART

[0002] A commodity inspecting equipment such as a weighing conveyor for,while articles are successively transported by a conveyor apparatus in aproduction line, measuring the weight thereof includes, for example, aconveyor apparatus of a type in which an endless flat belt or the likeis trained as a transport belt between a pair of rollers supported by aframe. One of the roller is a drive roller to which a driving force froma drive source such as a motor for moving the transport belt, and as abelt for transmission of the driving force an endless belt or the likeis trained between a pulley, mounted coaxially on the drive roller, anda pulley mounted on a drive shaft of the drive source.

[0003] The conveyor apparatus is coupled with a free end side of anelastic element so that it can serve as a load to a load cell as a loaddetector. A fixed end side of the elastic element is coupled with afixed member such as a leg member, a fixed frame, a fixed bracket or thelike. The load cell is generally accommodated within a housing so thatit will not be affected by an external environment such as moisture,dusts and others.

[0004] A relation in position between the conveyor apparatus and thehousing is such that since a space above the conveyor apparatus isrequired to be open wide in view of articles to be weighed being placedon the conveyor apparatus and since measurements would result in anerror when foreign matter falls onto the conveyor apparatus, theconveyor apparatus is generally disposed immediately above the housingor in side by side fashion relative to the housing. Accordingly,hitherto, the housing has an opening defined on a top surface or a sidesurface, and a support member for the support of the conveyor apparatusis passed through the opening so as to extend outwardly from the topsurface or side surface of the housing. One end side of the supportmember is connected with the free end side of the elastic element,whereas the other end side thereof extends upwardly or laterally towardsthe conveyor apparatus, and the opening through which the support memberextends is closed by a diaphragm.

[0005] In the meantime, this type of the weighing conveyor is sometimeused for transport and weighing of food materials and, in such case, awater component and/or dregs of the food materials may fall and/orscatter onto the housing to deposit on surfaces of the housing. However,if the top surface or side surface of the housing has the openingthrough which the support member extends and the diaphragm or the like,the dregs deposited thereon tend to easily accumulate, resulting inproliferation of unwanted bacteria to such an extent as to result indegradation of sanitary conditions and also to perforation in thediaphragm as a result of the dregs or the like having been bitten. Also,even where a cleaning work is regularly performed using a cleansingliquid or the like, a surface structure of the top surface or sidesurface of the housing is complicated, resulting in the cleaningcapability of the opening, diaphragm and their surroundings beingreduced.

[0006] As a technique capable of dealing with the foregoing problems,there is what is disclosed in the Japanese Laid-open Patent PublicationNo. 9-297051. This technique is such that while the load cell isaccommodated within a housing, a member for connecting a fixed endportion of an elastic element to a fixed member external to the housingis passed from a lower surface of the housing to the outside. By sodoing, neither the opening nor the diaphragm is positioned above the topsurface or side surface of the housing, resulting in improvement incapability of being cleaned.

[0007] However, in the technique disclosed in the above mentionedpublication, the fixed end portion of the elastic element is connectedwith the fixed member external to the housing and the free end portionis connected with the housing. Also, a support member is mounted on asurface of the housing and the conveyor apparatus is supported by thehousing. Accordingly, in addition to the weight of the conveyorapparatus, the weight of the support member or the weight of a drivetransmission mechanism, such as the drive motor, the drive transmittingbelt and pulleys or the like, the weight of the housing is loaded on theload cell as a tare weight and, therefore, the tare weight tends tobecome heavy, accompanied by reduction in natural frequency of ameasurement system of the weighing conveyor, which in turn results inlowering of the weighing accuracy.

[0008] Also, in this weighing conveyor, the drive shaft of the drivemotor extend in a direction perpendicular to the direction in which theelastic element of the load cell displaces upon receipt of a load. Forthis reason, the direction in which a portion of the centrifugal forcegenerated as a result of rotation of the drive shaft acts coincides withthe above mentioned direction of displacement of the elastic element.Accordingly, there has been a problem in that a weight signal outputtedfrom the load cell contains noises and, therefore, the weighing accuracytends to be lowered.

[0009] On the other hand, since the load cell is downwardly loaded witha load of the articles by the effect of a gravitational force, thedirection in which the elastic element displaces during a load detectionlie in a direction up and down. In other words, hitherto, in this typeof the weighing conveyor, a transport surface of the conveyor apparatuslies perpendicular to the direction of displacement of the elasticelement and the longitudinal axis of the drive shaft of the drive sourcelie parallel to the transport surface of the conveyor apparatus.

[0010] In view of the foregoing, in the event that a centrifugal forceis generated as a result of rotation of the drive shaft of the drivesource, accompanied by the generation of vibration, a portion of thedirection of the vibration induced by the centrifugal force acts also ina direction up and down. Since the up and down direction lie in thedirection in which the elastic element of the load cell displaces duringthe load detection, a change in load brought about by the vibrations isdetected by the load cell, with the consequence that the weight signalfrom the load cell contains noises, resulting in reduction of theweighing accuracy.

[0011] The more considerable the fluctuation of the drive shaft beingdriven, the more considerable the vibration brought about by the effectof the centrifugal force. In other words, in the event that the mass ofthe rotating element is in an unbalanced state with respect to thecenter of rotation thereof or the drive shaft fluctuate about thelongitudinal axis thereof during rotation thereof, the noises tend tobecome paramount.

[0012] In order to alleviate the above discussed problems, a techniquedisclosed in, for example, the Japanese Laid-open Patent Publication No.8-136330 may be employed. In other words, in addition to a firststandard load cell displaceable up and down to detect the weight of anarticle to be weighed, a second load cell is used and operable todisplace in a horizontal direction parallel to a direction of transport.This second load cell is used to detect a vibration acting in thetransport direction as a result of rotation of a rotary element. Sincethe vibration generated therein is a centrifugal force, it has an equalmagnitude in all directions within a plane perpendicular to a plane oftransport. Accordingly, by subtracting the vibration detected by thesecond load cell from a weight signal detected by the first load cellafter the phase relationship between them has been rectified, noisesresulting from the vibration can be eliminated.

[0013] However, with the known technique, plural load cells are requiredand, accordingly, not only does a hardware aspect become complicated,but also a software aspect of a signal processing for processing theweight signal becomes complicated, resulting in disadvantages in termsof cost. In view of this, there is a need to simplify the structureenough to avoid reduction in weighing accuracy which would otherwiseresults from containment of noises in the weight signal outputted from aload detector as a result of a rotatory vibration of the drive source.

[0014] Also, in this type of weighing conveyor, since the load cell, thedrive motor and the drive transmission mechanism are all disposedbetween upper and lower runs of the transport belt, the conveyorapparatus tends to have an increased size particularly a heightwisedirection thereof. Accordingly, since the natural frequency of theweighing conveyor decreases as a result of increase of the weight of theconveyor apparatus, that is, the tare weight, a low pass filter having ahigh cutoff frequency, for example, cannot be used. For this reason, theresponse of the filter does not increase so much and a filter processingtime does not decrease so much, and accordingly, a high speed weighingoperation is hampered.

[0015] Accordingly, the present invention has been devised in view ofthe foregoing problems and is intended to increase the accuracy ofinspection including the weighing accuracy. Hereinafter, the presentinvention will be described in detail, including the underlyingproblems.

DISCLOSURE OF THE INVENTION

[0016] In order to alleviate the foregoing problems, an inspectingmachine according to a first aspect of the present invention is aweighing conveyor characterized in that it includes a conveyor apparatusfor successively transporting articles to be weighed, a load detectorfor detecting a weight of the articles to be weighed that aresuccessively transported by the conveyor apparatus, and a housing foraccommodating the load detector, wherein a fixed end of the loaddetector is connected with the housing and a free end thereof isconnected with a support member for supporting the conveyor apparatus,said support member protruding outwardly from a bottom surface of thehousing.

[0017] According to the first aspect, since the support member forconnecting the load detector, accommodated within the housing, and theconveyor apparatus together is so configured as to protrude outwardlyfrom the bottom surface of the housing, neither from a top surface ofthe housing nor from a side surface thereof, there is no need to providean opening and a diaphragm in the top or side surface of the housing forpassage of the support member therethrough.

[0018] Also, since it is not the structure in which the support memberis provided in the housing and the conveyor apparatus is supported bythe housing, there is no need to assembly various members on a surfaceof the housing. Accordingly, the housing can have a surface neat infinish and with neither projection nor indentation and, therefore, anypossible deposition, stay and biting of the dregs of the article to beweighted can be suppressed. Also, a cleaning work is easy to perform,resulting in increase of a cleaning capability.

[0019] Also, since the housing is connected with the fixed end of theelastic element, no weight of the housing will be added to a tare weightand the tare weight does not therefore increase, resulting in increaseof the weighing accuracy.

[0020] In a preferred embodiment of the above described first aspect,the conveyor apparatus is arranged immediately above the housing and thesupporting member after having protruded outwardly from the bottomsurface of the housing extends upwardly of the housing towards theconveyor apparatus.

[0021] According to this embodiment, by causing the support member onceextending downwardly from the housing is bent so as to extend upwardly,the conveyor apparatus can be disposed immediately above the housing asusual. As a result thereof, a space above the conveyor apparatus is leftwide open and the possibility of foreign matter falling from the housingonto the conveyor apparatus is avoided and, as a result, the increase ofthe weighing accuracy can be expected.

[0022] In another preferred embodiment of the above described firstaspect, a surface of the housing confronting the conveyor apparatus isdefined by a downwardly continuously inclined face.

[0023] According to this embodiment even though dregs and others of thearticle to be weighed that is transported by the conveyor apparatusfalls or scatter and then deposit on a surface of the housing, they willslip downwardly without being stayed or stagnated. Accordingly,inconveniences such as degradation of the sanitary condition and/orproliferation of unwanted bacteria can advantageously be avoided.

[0024] In a further preferred embodiment of the above described firstaspect, a drive source for driving the conveyor apparatus isaccommodated within the housing.

[0025] According to this embodiment, since arrangement has been madethat the drive source such as a motor for driving the conveyor apparatusis also accommodated within the housing, no separate second housing foraccommodating the drive source is needed. Accordingly, the structure ofthe weighing conveyor as a whole can be simplified and this contributesto alleviation of the problem associated with deposition of the dregsand the cleaning capability.

[0026] Also, since electric lines or the like for the drive source donot expose themselves to the outside of the housing, this renders asurface shape to be neat and the problem associated with deposition ofthe dregs and the cleaning capability can be alleviated. In addition,the electric lines or the like need not be passed through the diaphragmto the outside and inside of the housing and, therefore, degradation ofthe water proof feature and the dust proof feature can be avoided.

[0027] In a still further preferred embodiment of the above describedfirst aspect, a drive transmission mechanism for transmitting a drivingforce of the drive source to the conveyor apparatus is accommodatedwithin the support member.

[0028] According to this embodiment, arrangement has been made that bythe utilization of the support member the drive transmission mechanismsuch as the drive transmission belt and pulleys are accommodatedtherein, a possible deposition of the dregs on the drive transmissionmechanism can be prevented. Also, no separate housing for accommodatingthe drive transmission mechanism need be prepared and the weighingconveyor as a whole can therefore be simplified, thereby lessening theproblem associated with the deposition of the dregs and the cleaningcapability.

[0029] A conveyor apparatus according to a second aspect of the presentinvention is characterized in that when a frame structure is bent, anendless transport belt can be mounted on or removed from at least onepair of rollers supported by the frame structure, wherein a bendingfulcrum of the frame structure lies at a location on one side of a lineof extension, connecting respective axes of rotation of the rollerstogether when the frame structure is not bent, adjacent one of runs ofthe transport belt, and wherein there is provided a stop member forinhibiting the frame structure from being bent towards the other of theruns of the transport belt.

[0030] According to this second aspect, since when the frame structureis not bent, the bending fulcrum of the frame structure does not lie onthe line of extension connecting the respective axes of rotation of therollers and lies on one side adjacent one of the belt runs, this framestructure when the frame structure is not bent is tended to necessarilybend towards the other of the belt runs under the influence of aresilient restoring force of the transport belt then held taut. At thistime, bending of the frame structure towards the other of the belt runsis barred and, therefore, when this frame structure when not bent ismaintained and locked in a condition in which it is not bent.

[0031] As a result thereof, no lock pins or the like such as dedicatedto avoid bending of the frame structure need be prepared separately andthe structure of the conveyor apparatus can be simplified, the number ofthe component parts used can be suppressed and the cleaning capabilityis increased, resulting in increase of the weighing accuracy. Also, whenthe transport belt is to be mounted and removed, there is no need tomanipulate any lock pin or the like and bending and straightening of theframe structure are sufficient, thereby simplifying the mounting andremoval of the transport belt.

[0032] In a preferred embodiment of the above described second aspect,the other of the runs of the transport belt is a transport surface forthe articles to be weighed.

[0033] According to this embodiment, by the action of a reactive forceof the gravity of the article being transported and a reactive forceresulting from the tension of the transport belt, the frame structuretends to bend in a direction in which the bending thereof is barred. Asa result thereof, any possible unlocking of the posture of the framestructure during the transport of the article can be avoided.

[0034] In another preferred embodiment of the above described secondconfiguration, the rollers are rotatable to allow the other of the runsof the transport belt to be held under tension.

[0035] According to this embodiment, since the force with which theframe structure tends to bend towards the other of the runs of the beltbecomes stronger, this leads to the fun maintenance and locking of theframe structure in the non-bending condition when the frame structure isnot bent.

[0036] In a further referred embodiment of the above described secondaspect, a biasing member is employed for biasing at least one of therollers in a direction required for a distance between the rollers toincrease.

[0037] According to this embodiment, since the transport belt is heldassuredly under tension at all times, the resilient restoring forcethereof can be secured and it is warranted that the frame structure islocked in the non-bending condition. Also, the tension of the belt and,hence, the resilient restoring force of the belt can be adjusted tovariably adjust the force with which the frame structure tends to bend.

[0038] In a still further preferred embodiment of the above describedsecond aspect, the transport belt is provided with indentationsengageable with the rollers to regulate displacement in position in adirection widthwise thereof

[0039] According to this embodiment, since any possible displacement inposition in a widthwise direction of the transport belt can beregulated, a tortuous motion of the belt can be suppressed to allow thebelt to be held stably under tension. As a result, the resilientrestoring force of the transport belt can be secured and, therefore,this warrants the locking of the frame structure in the non-bendingcondition.

[0040] In a still further preferred embodiment of the above describedsecond aspect, the frame structure is provided with roofing member forsupporting the run of the transport belt from backside thereof andwherein the stop member is defined by the roofing members.

[0041] According to this embodiment, where the roofing members areemployed for supporting the run of the transport belt from rear toprevent the transport belt from being slackened to thereby facilitate asmooth transport of the article, the stop member is concurrently servedby the utilization of the roofing members and, therefore, not only canthe structure be simplified, but also the number of the component partsneeded can be suppressed.

[0042] It is to be noted that the roofing members are exclusivelyutilized to stabilize a posture of the article to be transported duringthe transport thereof. In the weighing conveyor, to allow the article tobe transported past a sensor or the like serving as an inspecting meanswhile the article is in a stabilized posture without being fallen downis important in realizing a stable and assured weighing operation of theweighing conveyor. In the weighing conveyor, it is because if thearticle (the article to be weighed) falls down on the transport conveyorduring the transport thereof, a weighing error may occur. On the otherhand, in the case of a foreign matter detecting system in which thearticle is transported by the conveyor apparatus the presence or absenceof foreign matter such as metallic particles mixed into the articlebeing transported is inspected magnetically or by the utilization of Xrays, it will constitute an error in detection of the foreign matter.

[0043] A conveyor apparatus according to a third aspect of the presentinvention is of a type wherein when a frame structure is bent, anendless transport belt can be mounted on or removed from at least onepair of rollers supported by the frame structure, said conveyorapparatus comprising a drive source for driving one of the rollers; apulley mounted on a drive shaft of the drive source; a pulley mountedcoaxial with one of the rollers; an endless drive transmitting belttrained between and around the pulleys, wherein a bending fulcrum of theframe structure lies at a location on one side of a line of extension ofrespective axes of rotation of the pulleys, when the frame structure isnot bent, adjacent one of runs of the drive transmitting belt; and astop member for inhibiting the frame structure from being bent towardsthe other of the runs of the drive transmitting belt.

[0044] According to this third aspect, in place of or in combinationwith the resilient restoring force of the transport belt trained betweenand around the rollers, and under the influence of the resilientrestoring force of the drive transmission belt for transmitting thedrive of the drive motor to the drive roller, the frame structure tendsto bend towards the other of the belt runs. Accordingly, so long as theframe structure is not bent, the condition in which they do not bend isfirmly maintained and is thus locked. Since the article to be weighedthat is placed on the transport belt can accordingly be transported in astable posture, the weighing accuracy can be increased.

[0045] Also, when the frame structure is bent, mounting and removal ofthe transport belt can be performed simultaneously with mounting andremoval of the drive transmission belt, respectively.

[0046] An article inspecting machine according to a fourth aspect of thepresent invention is equipped with the conveyor apparatus according tothe above described second aspect.

[0047] In a preferred embodiment of the above described fourth aspect,there is provided an engagement for supporting a conveyor apparatus whenengaged with the conveyor apparatus, and wherein the conveyor apparatusand the engagement are engaged with each other when a frame structure ofthe conveyor apparatus is not bent, but are disengaged from each otherwhen the frame structure of the conveyor apparatus is bent.

[0048] According to this embodiment, when the frame structure of theconveyor apparatus is extended to a straight shape, mounting of thetransport belt onto the conveyor apparatus and mounting of the conveyorapparatus onto the inspecting machine can be performed simultaneously.Also, when the frame structure of the conveyor apparatus is bent,removal of the transport belt from the conveyor apparatus and removal ofthe conveyor apparatus from the inspecting machine can also be performedsimultaneously.

[0049] As a result thereof, there is no need to use separately anyfixture or the like dedicated for use in installing the conveyorapparatus onto the inspecting machine and, therefore, not only can thestructure of the article inspecting machine be simplified, but also thenumber of component parts needed can be suppressed to facilitatecleaning and to suppress any reduction in weighing accuracy. Also, whenthe conveyor apparatus is to be removed, there is no need to manipulateany fixture or the like and selective straightening or bending of theframe structure of the conveyor apparatus is sufficient and, thus, theoperation to remove the conveyor apparatus can be simplified. In otherwords, the maintenance and the cleaning capability can be considerablyincreased.

[0050] An inspecting machine according to a fifth aspect of the presentinvention is a weighing conveyor for weighing a weight of an article tobe weighed while the article to be weighed is transported, whichweighing conveyor is characterized by including a conveyor apparatus fortransporting the article to be weighed and having a transport surfacelaid horizontally; a drive source for driving the conveyor apparatus,and a load detector for supporting the conveyor apparatus and the drivesource and for detecting the weight of the article to be weighed that issupported and transported by the conveyor apparatus, in terms of up anddown displacement thereof, an axis of rotation of the drive source beingarranged parallel to a direction of such displacement.

[0051] In a preferred embodiment of the above described fifth aspect,the drive source is arranged on a free end of the load detector.

[0052] Also, in another preferred embodiment of the above describedfifth aspect, a drive transmission mechanism for transmitting a drivingforce of the drive source to the conveyor apparatus is employed, wherebyan axis of a rotatory drive force generated by the drive source isconverted into a direction parallel to the transport surface by thedrive transmission mechanism.

[0053] The weighing apparatus according to the present invention ischaracterized in that it is equipped with the weighing conveyoraccording to the above described fifth aspect. This weighing conveyorcan be optimally used particularly as a weighing apparatus (a weightchecker).

[0054] According to the above described fifth aspect, where thetransport surface of the conveyor apparatus lie perpendicular to thedirection of displacement of the load detector, the axis of rotation ofthe drive source is rendered to be parallel to the direction ofdisplacement, not parallel to the transport surface. In other words, thedrive source is so disposed that the axis of rotation of the drivesource can lie parallel to the direction of displacement of the loaddetector.

[0055] By so designing, the direction in which the rotational vibrationof the drive shaft of the drive source acts and the direction ofdisplacement of the load detector lie perpendicular to each otherwithout coinciding with each other. Accordingly, it is possible toprevent the load detector from detecting vibration noises and,therefore, no extra external noises will not appear in the weightsignal, thereby increasing the weighing accuracy.

[0056] Also, since the drive source is merely disposed so that the driveshaft of the drive source can extend in a direction parallel to thedirection of displacement of the load detector, the hardware structurewill not be complicated. Also, the weight signal can be used by itselfand, therefore, no software structure of a signal processing is notcomplicated as well. In addition, since the transport surface isdisposed horizontally, as compared with the type in which, for example,a pair of transport surfaces are laid vertically in face-to-facerelation with each other with the article to be weighed beingtransported while sandwiched between the transport surfaces, a diversityof articles to be weighed can be transported.

[0057] Also, as the drive source, which is a major source of drivenoises and which is a heavy item is disposed adjacent the free end ofthe load detector, the center of gravity of the drive source approachesthe center of moment of the load detector and, therefore, the influencewhich would be brought about by an external disturbing noises to theload detector can be reduced. Moreover, even though the drive sourcewhich is the source of the drive noises exists at the free end, the loaddetector would not adversely affected by the drive noises since thedirection in which the vibration acts is different from the direction ofdetection of the load detector.

[0058] In addition, where the drive transmission mechanism fortransmitting the drive force of the drive source to the conveyorapparatus is employed so that by this drive transmission mechanism theaxis of rotational drive force generated by the drive source can beconverted into a direction parallel to the transport surface, the driveforce of the drive source can be assuredly transmitted to the conveyorapparatus while the direction in which the axis of the rotational driveforce generated by the drive source is properly corrected by the drivetransmission mechanism.

[0059] In other words, since the axis of rotation of the drive source islaid parallel to the direction of displacement of the load detector, theaxis of the rotational drive force initially generated by the drivesource and the transport surface of the conveyor apparatus lieperpendicular to each other and do not therefore coincide with eachother. Accordingly, by converting the axis of the rotational drive forceinto the direction parallel to the transport surface of the conveyorapparatus by the utilization of the drive transmission mechanism that isdisposed between the drive source and the conveyor apparatus, a smoothdrive transmission can be realized. By employing such structure, it ispossible to realize versatile transport.

[0060] An inspecting machine according to a sixth aspect of the presentinvention is a weighing conveyor for weighing a weight of an article tobe weighed while the article to be weighed is transported, whichweighing conveyor is characterized by including a conveyor apparatus fortransporting the article to be weighed; a drive source for driving theconveyor apparatus; a drive transmitting mechanism for transmitting adrive force of the drive source to the conveyor apparatus; and a loaddetector for supporting the conveyor apparatus, the drive source and thedrive transmitting mechanism and for detecting the weight of the articleto be weighed that is supported and transported by the conveyorapparatus, wherein the conveyor apparatus is disposed above the loaddetector, the drive source is disposed at a location substantially levelwith the load detector, or below the load detector, with respect to anup and down direction, and the drive transmission mechanism is disposedso as to extend between a position below the load detector and aposition above the load detector with the load detector interveningtherebetween, such that a composite center of gravity of the conveyorapparatus, the drive source and the drive transmission mechanism isbrought to a position in a vicinity of a center of moment of the loaddetector in the up and down direction.

[0061] An inspecting machine according to a seventh aspect of thepresent invention is a weighing conveyor for weighing a weight of anarticle to be weighed while the article to be weighed is transported asis the case with the sixth aspect, which weighing conveyor ischaracterized by including a conveyor apparatus for transporting thearticle to be weighed; a drive source for driving the conveyorapparatus; a drive transmitting mechanism for transmitting a drive forceof the drive source to the conveyor apparatus; and a load detector forsupporting the conveyor apparatus, the drive source and the drivetransmitting mechanism and for detecting the weight of the article to beweighed that is supported and transported by the conveyor apparatus,wherein the conveyor apparatus is disposed below the load detector, thedrive source is disposed at a location substantially level with the loaddetector with respect to an up and down direction, and the drivetransmission mechanism is disposed so as to extend between a positionbelow the load detector and a position above the load detector with theload detector intervening therebetween, such that a composite center ofgravity of the conveyor apparatus, the drive source and the drivetransmission mechanism is brought to a position in a vicinity of acenter of moment of the load detector in the up and down direction.

[0062] An inspecting machine according to an eighth aspect of thepresent invention is a weighing conveyor for weighing a weight of anarticle to be weighed while the article to be weighed is transported asis the case with the sixth aspect, which weighing conveyor ischaracterized by including a conveyor apparatus for transporting thearticle to be weighed; a drive source for driving the conveyorapparatus; a drive transmitting mechanism for transmitting a drive forceof the drive source to the conveyor apparatus; and a load detector forsupporting the conveyor apparatus, the drive source and the drivetransmitting mechanism and for detecting the weight of the article to beweighed that is supported and transported by the conveyor apparatus,wherein the load detector is arranged at a location substantiallyintermediate of the conveyor apparatus with respect to a direction oftransport of the article to be weighed, the drive source is arrangedadjacent the load detector and the drive transmission mechanism isarranged so as to extend between a position downstream of the directionof transport and a position upstream of the direction of transport withthe load detector intervening therebetween, such that a composite centerof gravity of the conveyor apparatus, the drive source and the drivetransmission mechanism is brought to a position in a vicinity of acenter of moment of the load detector in the transport direction.

[0063] An inspecting machine according to a ninth aspect of the presentinvention is a weighing conveyor for weighing a weight of an article tobe weighed while the article to be weighed is transported as is the casewith the sixth aspect, which weighing conveyor is characterized byincluding a conveyor apparatus for transporting the article to beweighed; a drive source for driving the conveyor apparatus; a drivetransmitting mechanism for transmitting a drive force of the drivesource to the conveyor apparatus; and a load detector for supporting theconveyor apparatus, the drive source and the drive transmittingmechanism and for detecting the weight of the article to be weighed thatis supported and transported by the conveyor apparatus, wherein the loaddetector is arranged substantially intermediate of the conveyorapparatus with respect to a transport widthwise direction of the articleto be weighed, the drive source is arranged at a location substantiallylevel with the load detector with respect to the transport widthwisedirection, and the drive transmission mechanism is arranged so as toextend between a position substantially level with the load detector anda position leftwards or rightwards of the transport widthwise direction,or so as to extend between respective positions leftwards and rightwardsof the transport widthwise direction with the load detector interveningtherebetween, such that a composite center of gravity of the conveyorapparatus, the drive source and the drive transmission mechanism isbrought to a position in a vicinity of a center of moment of the loaddetector in the transport widthwise direction.

[0064] In a preferred embodiment of the sixth aspect, the load detectoris arranged substantially intermediate of the conveyor apparatus withrespect to the direction of transport of the article to be weighed, thedrive source is positioned adjacent the load detector, and the drivetransmission mechanism is arranged so as to extend between respectivepositions upstream and downstream of the direction of transport with theload detector intervening therebetween, such that the composite centerof gravity of the conveyor apparatus, the drive source and the drivetransmission mechanism is brought to the position in the vicinity of thecenter of moment of the load detector also in the direction oftransport.

[0065] In another preferred embodiment of the sixth aspect, the loaddetector is arranged substantially intermediate of the conveyorapparatus with respect to the transport widthwise direction, the drivesource is positioned at a location substantially level with the loaddetector with respect to the transport widthwise direction, and thedrive transmission mechanism is arranged so as to extend between alocation substantially level with the load detector with respect to thetransport widthwise direction and a location leftward or rightward ofthe transport widthwise direction, or so as to extend between respectivelocations leftwards and rightwards of the transport widthwise directionwith the load detector intervening therebetween, such that the compositecenter of gravity of the conveyor apparatus, the drive source and thedrive transmission mechanism is brought to the position in the vicinityof the center of moment of the load detector also in the transportwidthwise direction.

[0066] The weighing apparatus of the present invention is featured inthat the weighing conveyor according to the sixth aspect is employed.This weighing conveyor is most suitably used particularly as a weighingapparatus (a weight checker).

[0067] In the weighing conveyor according to any one of the previouslydescribed sixth to ninth aspects, since arrangement of the conveyorapparatus, the drive source and the drive transmission mechanismrelative to the load detector is comprehensively taken intoconsideration and the weights are uniformly balances, the center ofgravity of the weighing conveyor is positioned in the vicinity of thecenter of moment of the load detector.

[0068] Accordingly, the center-to-center distance between the center ofgravity of the conveyor apparatus and the center of moment of the loaddetector can be reduced to minimize the force of moment acting on theload detector. As a result thereof, the frequency region of the noisecomponent to be removed can be increased to reduce the filter processingtime and, therefore, a high speed weighing operation can be attained tothereby increase the weighing accuracy.

[0069] Also, particularly in the weighing conveyor according to thesixth aspect, when the drive transmission mechanism is to be disposedbetween the conveyor apparatus, positioned above the load detector, andthe drive source positioned at a location substantially level with theload detector or below the load detector, and when the drivetransmission mechanism is disposed so as to extend up and down with theload detector intervening therebetween, the weights in the up and downdirection of the conveyor apparatus can be balanced and the center ofgravity of the conveyor apparatus can be brought close to the center ofmoment of the load detector with respect to the up and down direction.

[0070] In the weighing conveyor according to the seventh aspect, whenthe drive transmission mechanism is to be disposed between the conveyorapparatus, positioned below the load detector and the drive sourcearranged at a location substantially level with the load detector, thedrive transmission mechanism is so arranged as to extend up and downwith the load detector intervening therebetween. Accordingly, theweights in the up and down direction of the conveyor apparatus are wellbalanced and the center of gravity of the conveyor apparatus can bebrought close to the center of moment of the load detector with respectto the up and down direction.

[0071] Also, in the weighing conveyor according to the eighth aspect,when the drive transmission mechanism is to be disposed between theconveyor apparatus, which has been disposed with its weight balanced inthe transport direction relative to the load detector, and the drivesource arranged at a location close to the load detector, the drivetransmission mechanism is so arranged as to extend in a directionparallel to the transport direction with the load detector interveningtherebetween. Accordingly, the weights in the transport direction of theconveyor apparatus are well balanced and the center of gravity of theconveyor apparatus can be brought close to the center of moment of theload detector with respect to the transport direction.

[0072] Again, in the weighing conveyor according to the ninth aspect,when the drive transmission mechanism is to be disposed between theconveyor apparatus, which has been disposed with its weight balanced inthe transport widthwise direction relative to the load detector, and thedrive source arranged at a location substantially level with the loaddetector in the transport widthwise direction, the drive transmissionmechanism is so arranged as to extend between the position substantiallylevel with the load detector in the transport widthwise direction andthe position either leftwards or rightwards thereof or as to extend in adirection parallel to the transport widthwise direction with the loaddetector intervening therebetween. Accordingly, the weights in thetransport widthwise direction of the conveyor apparatus are wellbalanced and the center of gravity of the conveyor apparatus can bebrought close to the center of moment of the load detector with respectto the transport widthwise direction.

[0073] Furthermore, in a preferred embodiment of the weighing conveyoraccording to the sixth aspect, the center of gravity of the conveyorapparatus is brought in the close vicinity of the center of moment ofthe load detector in two dimensions including the up and down directionand the transport direction. Hereinafter, the preferred embodiments ofthe present invention, including their underlying problems will bediscussed in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In any event, the present invention will become more clearlyunderstood from the following description of preferred embodimentsthereof, when taken in conjunction with the accompanying drawings.However, the embodiments and the drawings are given only for the purposeof illustration and explanation, and are not to be taken as limiting thescope of the present invention in any way whatsoever, which scope is tobe determined by the appended claims. In the accompanying drawings, likereference numerals are used to denote like parts throughout the severalviews, and:

[0075]FIG. 1 is a schematic perspective view of a weighing apparatusutilizing a weighing conveyor according to the present invention;

[0076]FIG. 2 is a top plan view showing the weighing conveyor with aportion of a conveyor apparatus removed;

[0077]FIG. 3 is a left side view showing the weighing conveyor with aportion thereof cut out;

[0078]FIG. 4 is a right side view of the weighing conveyor, showing astructure inside a housing in a fragmentary sectional representation;

[0079]FIG. 5 is a longitudinal sectional view of the weighing conveyor,as viewed from an upstream side towards a downstream side;

[0080]FIG. 6 is a side view, on an enlarged scale, showing a supportstructure for a driven roller of the conveyor apparatus of the weighingconveyor;

[0081]FIG. 7 is a sectional view, on an enlarged scale, showing anengagement between a transport belt and a roller;

[0082]FIG. 8 is a fragmentary view, on an enlarged scale, showing aninner surface of an upper end of an arm forming a part of a supportmember;

[0083]FIG. 9 is an explanatory diagram showing how the conveyorapparatus is assembled;

[0084]FIG. 10 is an explanatory diagram used to explain the operation ofthe conveyor apparatus;

[0085]FIG. 11 is an explanatory diagram showing how the weighingconveyor is assembled;

[0086]FIG. 12 is a schematic side view of the conveyor apparatusaccording to another preferred embodiment of the present invention,showing the conveyor apparatus before being assembled;

[0087]FIG. 13 is a diagram showing how the conveyor apparatus isassembled;

[0088]FIG. 14 is a schematic side view showing a modification of theconveyor apparatus shown in FIG. 12;

[0089]FIG. 15 is a schematic side view of the conveyor apparatusaccording to a further preferred embodiment of the present invention;

[0090]FIG. 16 is a right side view of the weighing conveyor showinganother aspect of the present invention, showing the structure insidethe housing in a partially cut-out sectional representation;

[0091]FIG. 17 is a longitudinal sectional view of the weighing conveyor,as viewed from an upstream side towards a downstream side;

[0092]FIG. 18 is a plan view of the conveyor apparatus of the weighingconveyor, showing a further aspect of the present invention with aportion cut out;

[0093]FIG. 19 is a right side view of the weighing conveyor, showing thestructure inside the housing in a partially cut-out sectionalrepresentation;

[0094]FIG. 20 is a longitudinal sectional view of the weighing conveyor,as viewed from an upstream side towards a downstream side; and

[0095]FIG. 21 illustrates a still further preferred embodiment of theweighing conveyor, with a transport mechanism disposed below a loaddetector.

BEST MODES FOR CARRYING OUT THE INVENTION

[0096] Hereinafter, a weighing conveyor according to a first aspect ofthe present invention will be described. In an embodiment shown in FIG.1, a weighing conveyor 2 is applied to a weight checker 1 which is aweighing apparatus. This weighing conveyor 2 includes a conveyorapparatus 3 of a flat belt type, and a housing 7 accommodating therein aload cell 5 serving as a load detector. The housing 7 is fixed on a pairof front and rear leg members 10 and 11. The weighing conveyor 2 isdisposed at a tail end of a production line and is operable, forexample, to measure, one at a time, the weight of bagged products Xwhich are articles to be weighed and which are supplied from a baggingand packaging machine (not shown), while the bagged products X aresuccessively transported by the conveyor apparatus 3 in a directionshown by the arrow A, and then to deliver the bagged products Xsuccessively onto, for example, a metal detector (not shown) or thelike.

[0097] As shown in FIG. 2, the conveyor apparatus 3 is of a structureincluding an endless flat belt 17 trained between and around front andrear rollers 13 and 15. The roller (front roller) 13 positioneddownstream with respect to the transport direction A is a drive rollerwhereas the roller (rear roller) 15 positioned upstream with respect tothe transport direction A is a driven roller. Positioned between theserollers 13 and 15 are five separated roofing plates 21 . . . 21, 23 and25.

[0098] Those roofing plates 21 . . . 21, 23 and 25 are elongated inforward and rearward direction and are juxtaposes in side by siderelation to each other. The three inner roofing plates 21 . . . 21 arepositioned immediately below an upper run of the transport belt 17 thatdefines a transport surface thereof to support the transport surface inits entire surface from below. The left and right roofing plates 23 and25 are positioned sidewise adjacent opposite ends of the rollers 13 and15, respectively, to partially support opposite side edge portions ofthe transport surface of the transport belt 17.

[0099] The transport belt 17 has a width somewhat greater than thelength of each of the rollers 13 and 15 and, as shown by 17 a in FIGS. 5and 7, left and right side edge portions of the transport belt 17 havetheir undersurfaces protruding outwardly. These protruding edge portions(indented) 17 a and 17 a are engaged with the opposite ends of each ofthe rollers 13 and 15, respectively. In this way, the transport belt 17does not undergo a tortuous run in a direction widthwise thereof, whichwould otherwise result in when the transport belt 17 displace sidewisehaving been disengaged form one or both of the rollers 13 and 15, and isproperly and stably trained between and around the rollers 13 and 15 atall times.

[0100] It is to be noted that the outer roofing plate 23 and 25 havetheir top surfaces formed with respective steps 23 a and 25 a foravoiding the adjacent protruding edge portions 17 a and 17 a of thetransport belt 17.

[0101] As shown in FIG. 5, each of the roofing plates 21 . . . 21, 23and 25 is so bent and so shaped as to represent a generally channelshaped cross section. These roofing plates 21 . . . 21, 23 and 25 are,as shown in FIG. 2, connected together by means of three L-sectionedbeams 31, 33 and 35. As shown in FIGS. 3 to 5, the left and rightroofing plates 23 and 25 have respective outer longitudinal walls 23 band 25 b that extend a substantial distance in a direction up and downto thereby define left and right side walls of the conveyor apparatus 3.

[0102] As shown in FIG. 2, the drive roller 13 positioned downstream hasstud shafts 13 a and 13 b protruding axially outwardly from the oppositeends thereof for rotation together therewith. Bearing units 37 and 39are fitted to a longitudinal wall of the L-sectioned beam 31 that ispositioned on the downstream side and the stud shafts 13a and 13b arerotatably supported respectively by these bearing units 37 and 39.

[0103] One 13 a of the stud shafts is accommodated within thecorresponding bearing unit 37. This bearing unit 37 has an outer surfaceformed with an engagement member 41 protruding outwardly therefrom. Incontrast, the other 13 b of the stud shafts extends through thecorresponding bearing unit 39. The bearing unit 39 has an outer surfacefrom which a free end 13 c of the stud shaft 13 b extending therethroughprotrudes outwardly. As shown in FIG. 3, the outwardly protruding end 13c of the stud shaft 13 b is so shaped as to have a rectangular crosssection.

[0104] The left and right roofing plates 23 and 25 serve not only tosupport the transport surface of the transport belt 17 from rear, butalso to provide left and right frames for the conveyor apparatus 3. Inother words, the drive roller 13 is rotatably supported by therespective frames 23 and 25 through the bearing units 37 and 39 and theL-sectioned beam 31.

[0105] On the other hand, as shown in FIG. 2, left and right endportions of the longitudinal wall 35 a of the upstream L-sectioned beam35 are bent to extend in an upstream direction to provide respectivebent pieces 35 b and 35 b to which brackets 51 and 51 are connected forpivotal movement about pin members 52 and 52, respectively. As shown inFIG. 6, each of the brackets 51 has an upstream side end representing asemicircular shape, and a slot 53 extending in a forward and rearwarddirection is defined in that upstream side end of the respective bracket51. Opposite free ends 15 b and 15 b of a shaft 15 a of the drivenroller 15 are passed through the respective slots 53 and 53.

[0106] As shown in FIG. 6, the free ends 15 b and 15 b of the shaft 15 aare so shaped as to have a rectangular cross section and are nottherefore rotatable within the associated slots 53 and 53, but aredisplaceable in the forward and rearward direction within those slots 53and 53. As shown in FIG. 2, the shaft 15 a extends axially through thedriven roller 15 which is in turn rotatable relative to the shaft 15 a.

[0107] The pair of the left and right brackets 51 and 51 referred toabove serve as frames of the conveyor apparatus 3. In other words, thedriven roller 15 is supported rotatably by those frames 51 and 51.

[0108] As shown in FIG. 2, a roofing plate 55 is jointed to respectivetop edges of the brackets 51 and 51. This roofing plate 55 extends adistance in a widthwise direction and has engagement members 57 and 57formed in left and right outer longitudinal walls thereof (See, also,FIGS. 3 and 4).

[0109] It is to be noted that as is the case with the left and rightouter roofing members 23 and 25 discussed hereinbefore, a step 55 a isformed on a top surface of the roofing member 55 to avoid the protrudingedge portions 17 a and 17 a at the undersurface of the transport belt 17(See, also, FIG. 6).

[0110] As shown in FIG. 6, each of the brackets 51 is provided with arespective spring 59, which is a biasing member for urging the shaft 15a of the driven roller 15 in an upstream direction and which has one endin abutment with the corresponding rectangular sectioned end 15 b of theshaft 15 a. The opposite end of the respective spring 59 is held inabutment with a plate member 61. The plate member 61 is in turnthreadedly engaged with a screw rod 63. The screw rod 63 is rotatablysupported by a bent piece 51 a of each of the brackets 51 and 51.

[0111] As shown in FIG. 5, each of the plate members 61 and 61 has oneside held in contact with the adjacent bracket 51. Accordingly, when thescrew rod 63 is rotated, the plate member 61 moves forwards orrearwards. As a result, the biasing force generated by the correspondingspring 59 can be adjusted to thereby adjust a pressing force pressingthe driven roller 15 in the upstream direction. In other words, thedistance between the drive roller 13 and the driven roller 15 can beadjusted variably. The driven roller 15 is held still at a position inequilibrium with the tension of the transport belt 17. Accordingly, eventhough the length of the transport belt 17 fluctuates, it is possiblefor the transport belt 17 to be held properly under a proper tension atall times.

[0112] Also, as shown in FIGS. 4 and 5, the housing 7 has a structureand an appearance in which a housing body 71 occupying a lower halfthereof and a covering member 72 occupying an upper half thereof andplaced above the housing body 71. Within the housing 7, an elasticelement 5 a of the load cell 5, which is a load detector, and a drivemotor 73, which is a drive source of the conveyor apparatus 3, areaccommodated.

[0113] As shown in FIG. 4, the elastic element 5 a has a stationary end5 b fixed to the housing body 71 through a fixing member 75. A free end5 c of the elastic element 5 a has the drive motor 73 assembled theretothrough a fixing member 77 and a bracket 79.

[0114] As shown in FIG. 5, the drive motor 73 is disposed with its driveshaft 73 a extending in the up and down direction. In particular, in theillustrated embodiment, the drive shaft 73 a of the drive motor 73extends downwards. A hollow spacer 81 is fitted to an undersurface ofthe bracket 79, and a gear box 83 is in turn coupled to a lower end ofthe spacer 81.

[0115] The gear box 83 extends through an opening 71 a defined in abottom surface of the housing body 71 so as to protrude outwardlydownwardly from the housing 7. A diaphragm 85 is interposed betweenrespective joint faces of the spacer 81 and the gear box 83. Thisdiaphragm 85 is also sandwiched between a peripheral lip region of theopening 71 a and a ring member 87 secured to such peripheral lip regionto thereby close the opening 71 a.

[0116] As shown in FIGS. 3 to 5, cylindrical hollow members 91 and 93extend horizontally from left and right side surface of the gear box 83,respectively. Of them, the cylindrical hollow member 91 extendingtowards the engagement members 41 and 57 secured to a side surface ofthe conveyor apparatus 3 so as to project therefrom has an extended endto which, as shown in FIGS. 4 and 5, an arm member 95 of a generallyV-shaped configuration as viewed from side is fitted (See, also, FIG.2). This arm member 95 is made up of arms 95 a and 95 b that extendslantwise upwardly in respective directions away from each other,respective free ends of those arms 95 a and 95 b having recesses 95 cand 95 d formed therein for receiving the associated engagement members41 and 57 of the conveyor apparatus 3.

[0117] On the other hand, as regards the cylindrical hollow member 93extending towards the engagement member 57 and the rectangular sectionedend 13 c of the stud shaft 13 b of the drive roller 13, both of whichare secured to the side surface of the conveyor apparatus 3, an armmember 97 of a generally V-shaped configuration as viewed from side isfitted to an extended end of the cylindrical hollow member 93 as shownin FIGS. 3 and 5 (See, also, FIG. 2). This arm member 97 is made up ofarms 97 a and 97 b that extend slantwise upwardly in respectivedirections away from each other, only the arm 97 b having a free endformed with a cutout 97 c for engagement with the engagement member 57of the conveyor apparatus 3.

[0118] In contrast thereto, the arm 97 a extending towards the end 13 cof the stud shaft 13 b has an outer surface to which an elongated covermember 99 is fitted, as shown in FIG. 5, to thereby define a sealedsmall room for accommodating a support plate 100 therein.

[0119] As shown in FIG. 5, the cylindrical hollow member 93 referred toabove accommodates therein a transmission shaft 101 having one endmounted with a bevel gear 103 that is in turn meshed with a bevel gear105 mounted fixedly on the drive shaft 73 a of the drive motor 73. Thetransmission shaft 101 in turn extends into the interior of the covermember 99 and is then rotatably supported by the support plate 100 orthe like. Within the interior of the cover member 99, a transmissionpulley 107 is mounted on the transmission shaft 101 for rotationtogether therewith.

[0120] On the other hand, as shown in FIG. 5, a second transmissionshaft 109, which is a rotary shaft, is rotatably supported by an upperportion of the support plate 100 at a location corresponding to the studshaft 13 b of the drive roller 13, and a second transmission pulley 111is fixedly mounted on such shaft 109. An endless timing belt 113 fortransmission of a drive force is trained between and around thetransmission pulleys 107 and 111.

[0121] It is to be noted that the second transmission shaft 109 extendsthrough the arm 97 a of the V-shaped arm member 97 inwardly towards theconveyor apparatus 3 and, as shown in FIG. 8, an extended portion 109 athereof is formed with a rectangular hole 109 b formed therein forreceiving the rectangular sectioned end 13 c of the stud shaft 13 b ofthe drive roller 13 (See, also, FIG. 2).

[0122] As discussed above, the spacer 81, the gear box 83, thehorizontally extending cylindrical hollow members 91 and 93, and theleft and right V-shaped arm members 95 and 97 and others are not onlysupport the conveyor apparatus 3, but also altogether constitute asupport member 120 for connecting the conveyor apparatus 3 to the freeend 5 c of the elastic element 5 a (See FIGS. 1 and 3 to 5). Not only isthe drive motor 73 housed within the housing 7, but the drivetransmission mechanism (shown by 130 in FIG. 5) including the shafts 101and 109, the pulleys 107 and 111 and the timing belt 113 and others fortransmitting the drive force of the drive motor 73 to the conveyorapparatus 3 is also accommodated within the housing 7.

[0123] Hereinafter, the operation of the weighing conveyor according tothe first aspect will be described.

[0124] In the first place, the conveyor apparatus 3 assumes ahorizontally straight position with a frame structure having the frames23, 25, 51 and 51 not being bent about the associated bending fulcrums52 and 52, and the transport belt 17 is trained under a proper tensionbetween and around the rollers 13 and 15. While in this condition, therectangular sectioned end 13 c of the stud shaft 13 b of the driveroller 13 of the conveyor apparatus 3 is inserted into the rectangularshaped hole 109 b formed in the extended end 109 a of the secondtransmission shaft 109 that extend inwardly from the downstream V-shapedarm 97 a.

[0125] Then, the engagement member 41 of the bearing unit 37 supportingthe opposite stud shaft 13 a of the drive shaft of the conveyorapparatus 3 similarly at the downstream side is engaged in the cutout 95c in the opposite V-shaped arm 95 a similarly at the downstream side.Thereafter, by lowering the conveyor apparatus 3, the left and rightengagement members 57 and 57 upstream of the conveyor apparatus 3 areengaged in the cutouts 95 d and 97 c in the similarly upstream V-shapedarms 95 b and 97 b, respectively. In this way, the conveyor apparatus 3is now supported by the support member 120, thereby completing theweighing conveyor 2 and, thus, the weight checker 1.

[0126] When the drive motor 73 is subsequently powered, the drive forceof the drive motor 73 is transmitted to the drive roller 13 through thebevel gears 105 and 103, the first transmission shaft 101, the firsttransmission pulley 107, the drive transmission timing belt 113, thesecond transmission pulley 111 and finally through the secondtransmission shaft 109, wherefore the upper transport surface of thetransport belt 17 travels in the transport direction A to successivelytransport the articles X to be weighed.

[0127] On the other hand, the support member 120 including the drivemotor 73, the spacer 81, the gear box 83, the cylindrical hollow members91 and 93, the V-shaped arms 95 and 97, the cover member 99 and others,the drive transmission mechanism 130 including the transmission shaft101, the pulley 107 and others, and the conveyor apparatus 3 areconnected with the free end 5 c of the elastic element Sa of the loadcell 5 through the fixing member 77 and the bracket 79, so that thetotal weight of those components are loaded at all times on the loadcell 5 as a tare weight. During the successive transport of the articlesX to be weighed, the weight of the article X to be weighed add to thetotal weight and, therefore, the weight of the article X to be weighedcan be detected by subtracting the tare weight from the gross weight.

[0128] Specifically, in this weighing conveyor 2 according to the firstaspect, in the structure including the conveyor apparatus 3 fortransporting the articles X to be weighed, the load cell 5 for detectingthe weight of each of the articles X to be weighed that are successivelytransported by the conveyor apparatus 3, and the housing 7 accommodatingthe load cell 5 , as shown in FIG. 4, the fixed end 5 b of the load cell5 is connected with the housing 7 while the free end 5 c is connectedwith the support member 120 for supporting the conveyor apparatus 3,with the support member 120 allowed to protrude outwardly from thebottom surface of the housing 7.

[0129] As a result, there is no need to provide the opening on the topand side surface of the housing 7 and the diaphragm. Also, since it isnot the structure wherein the support member is provided on a side ofthe housing 7 so that the conveyor apparatus 3 can be supported by thehousing 7, there is no need to install the support member and otherassociated members on any surface of the housing 7. Accordingly, thehousing 7 can provide a shape comfortable to look with neitherprojection nor indentation formed on any surface of the housing 7,thereby minimizing the possibility of the dregs of the articles X to beweighed left deposited, stayed still and/or bitten and, also, enhancingcleaning of the housing 7 and, hence, cleaning of the weighing conveyor2 in its entirety with the cleaning capability consequently increasedconsiderably. Also, since the conveyor 3 can be easily removed, thisfeature enables the cleaning capability of the housing 7 and, hence, theweighing conveyor 2 to be increased.

[0130] In addition, on one hand, since the housing 7 is connected to thefixed end 5 b of the elastic element 5 a, the weight of the housing 7 isin no way added to the tare weight and, therefore, increase of the tareweight is accordingly suppressed, permitting the weighing accuracy ofthe weighing conveyor 2 to be increased.

[0131] In the weighing conveyor 2 according to this first aspect, afterthe conveyor apparatus 3 has been mounted immediately above the housing7 and the support member 120 has subsequently been allowed to protrudeoutwardly from the bottom surface of the housing 7, it is allowed toextend upwardly of the housing 7 towards the conveyor apparatus 3.

[0132] In other words, by allowing the support member 120, once allowedto extend downwardly from the housing 7, to be turned backwards so as toextend upwardly, the conveyor apparatus 3 can be arranged immediatelyabove the housing 7 and, as a result thereof, the space above theconveyor apparatus 3 can be left open wide and, therefore, not only canthe articles X to be weighed be successively transported withoutencountering with any obstruction, but also the inconvenience can beavoided in which the weighed value would be adversely affected as aresult of foreign matter falling from the housing 7 onto the conveyorapparatus 3.

[0133] Also, in the weighing conveyor 2 according to the first aspect, asurface of the housing 7 confronting the conveyor apparatus 3 is definedby an inclined surface continuing downwardly. In other words,particularly as shown in FIG. 1 and 5, the covering member 72 formingthe upper half of the housing 7 is so shaped as to represent a gentlehill.

[0134] Accordingly, even though dregs or the like of the articles X tobe weighed that are successively transported by the conveyor apparatus 3fall and/or are scattered to deposit on the surface of the housing 7,they can slip downwardly from the housing 7 and will not remaindeposited or staying on the surface of the housing 7. Therefore,inconveniences such as degradation of the sanitary condition and/orproliferation of unwanted bacteria can advantageously be avoided.

[0135] Also, in the weighing conveyor 2 according to the first aspect,the drive motor 73 for driving the conveyor apparatus 3 is as wellaccommodated within the housing 7. Accordingly, there is no need to usea second separate housing for accommodating the drive motor 73, makingit possible to simplify the entire structure of the weighing conveyor 2and, therefore, the problem associated with deposition of the dregs orthe like can be alleviated to increase the cleaning capability.

[0136] At the same time, since, for example, electric lines extendingfrom and to the drive motor 73 can be disposed only within the housing 7without being exposed to the outside, this feature enables the surfaceshape of the housing 7 to be neat and the problem associated withdeposition of the dregs can be alleviated to thereby increase thecleaning capability. In addition, the electric lines and others need notbe passed inwardly and outwardly of the housing 7 through the diaphragm85 and, therefore, the problem associated with reduction in water anddust proof properties of the housing 7 can be avoided, too.

[0137] Yet, in the weighing conveyor 2 according to the first aspect,the drive transmission mechanism 130 for transmitting the drive force ofthe drive motor 73 to the conveyor apparatus 3 is accommodated withinthe support member 120. Accordingly, since the drive transmissionmechanism 130 including the drive transmission belt 113, the pulleys 107and 111 and others are accommodated by the utilization of the supportmember 120, any possible deposition of the dregs of the articles X onthe drive transmission mechanism 130 itself can be avoided. Also, thereis no need to use any separate housing for accommodating solely thedrive transmission mechanism 130, allowing the weighing conveyor 2 as awhole to be simplified in structure and, accordingly, not only theproblem associated with a propensity of the dregs of the articles Xbeing deposited, but also the problem associated with the cleaningcapability for removing the deposited dregs can be alleviated.

[0138] In the next place, the weighing conveyor 2 equipped with theconveyor apparatus according to a second aspect will be described. Whilethe basic structure of the weighing conveyor 2 is identical with thataccording to the first aspect, the following is featured.

[0139] In other words, in the weighing conveyor equipped with theconveyor apparatus according to the second aspect, the frames 23 and 25that form the roofing members of the previously described conveyorapparatus 3 and the frame 51 that forms the bracket used in thepreviously described conveyor apparatus 3 are so bendable that whenthose frames are bent, the endless transport belt 17 can be removed fromat least the pair of the rollers 13 and 15 supported by those frames,and the bending fulcrums 52 about which the frames 23, 25, 51 and 51 canbe bent are arranged offset on one side of the line of extension L,connecting respective axes of rotation of the rollers 13 and 15 when theframes are not bent, adjacent the belt travel surface while a stopmember (the roofing members 23 and 25) is employed for inhibiting theframes 23, 25, 51 and 51 from being bent towards the opposite side ofthe belt travel surface.

[0140] Also, in the weighing conveyor equipped with the conveyorapparatus according to a third aspect, in the structure including thedrive motor 73 which is the drive source for driving one of the rollers13 and 15, the pulley 107 coupled with the drive shaft 73 a of the drivemotor 73, the pulley 111 provided coaxial on one of the rollers 13 and15, and the endless drive transmission timing belt 113 trained betweenand around the pulleys 107 and 111, the bending fulcrums 52 of theframes 23, 25, 51 and 51 are arranged offset on one side of the line ofextension L1 of the shaft 109, which is a rotary shaft for the pulley111 when the frames are not bent, adjacent the belt travel surface whilea stop member (the roofing members 23 and 25) is employed for inhibitingthe frames 23, 25, 51 and 51 from being bent towards the opposite sideof the belt travel surface.

[0141] More specifically, in the conveyor apparatus according to thesecond aspect, as shown in FIGS. 3 and 4, the bending fulcrums 52 and 52of the frames 23, 25, 51 and 51 do not lie on the line of extension Lconnecting between the stud shaft 13 a (13 b) serving as the axis ofrotation of the drive roller 13 and the stud shaft 15 a serving as theaxis of rotation of the driven roller 15, but are positioned offsetdownwardly therefrom. Also, in the conveyor apparatus according to thethird aspect, the bending fulcrum 52 is positioned offset downwardlyfrom the line of extension of the shaft 109 which is a rotary shaft forthe pulley 111 for rotating the drive roller 13. The bending fulcrum 52referred to above is the fulcrum about which the frames 23 and 25 forrotatably supporting the drive roller 13 and the frames 51 and 51 forrotatably supporting the driven roller 15 bend.

[0142] Accordingly, as shown in FIGS. 3 and 4, when the frames 23, 25,51 and 51 extend straight without being bent, the distance between therollers 13 and 15 is so long enough to allow the transport belt 17,trained between and around the rollers 13 and 15, to be held underproper tension. Accordingly, the articles X to be weighed can beproperly transported by the transport belt 17 successively.

[0143] On the other hand, by the action of a resilient restoring forceof the transport belt 17 then held under tension, the frames 23, 25, 51and 51 tend to bend about the bending fulcrums 52 and 52. In such case,since the bending fulcrums 52 and 52 are offset downwardly from thecenter line L connecting between the rollers 13 and 15, the frames 23,25, 51 and 51 are likely to bend towards the upper transport surface asshown by the arrows B and B in FIGS. 3 and 4.

[0144] At this time, as shown in FIGS. 2, 3 and 6, respective uppersurfaces of the roofing members 23 and 25, which are the frames,respectively, extend upstream towards above the brackets 51 and 51 whichare similarly the frames. Consequently, respective upper edges of ones51 and 51 of the frames (brackets) are brought into contact with theothers 23 and 25 of the frames (left and right outer roofing members,that is, stop members), wherefore the frames 23, 25, 51 and 51 areinhibited from being bent further towards the upper transport surface asshown by the arrows B and B.

[0145] Hereinafter, the operation of the weighing conveyor 2 equippedwith the conveyor apparatus according to any one of the second and thirdaspects will be described with particular reference to FIGS. 9 to 11.

[0146] When the conveyor apparatus 3 is desired to be set in positionready for use with the transport belt 17 mounted thereon, the frames 23,25, 51 and 51 have to be bent about the bending fulcrums 52 and 52 in adirection towards a lower run of the transport belt 17 opposite to thetransport surface thereof as shown in FIG. 9 and, while in thiscondition, the transport belt 17 is trained between and around therollers 13 and 15. Since at this time the distance between the rollers13 and 15 is shortened, the transport belt 17 can be mounted easily in aloosened state.

[0147] Thereafter, the frames 23, 25, 51 and 51 are pivoted inrespective directions shown by the arrows B and B about the bendingfulcrums 52 until they assume a straight position as shown in FIG. 10.When the frames 23, 25, 51 and 51 assume the straight position extendinghorizontally without bending at the bending fulcrums 52 and 52, thedistance between the rollers 13 and 15 is lengthened and, accordingly,the transport belt 17 is held under a proper tension having been stablytrained between and around the rollers 13 and 15.

[0148] On the other hand, as a reactive force resulting from the tensionof the transport belt 17, an elastic restoring force of the transportbelt 17 acts on the frames 23, 25, 51 and 51. An external stress thereofurges the frames 23, 25, 51 and 51 to rock about the bending fulcrums 52and 52 in the directions B and B or the direction counter to thetransport surface of the belt 17. However, since as hereinabovediscussed, the bending fulcrums 52 and 52 do not lie on the center lineL connecting between the rollers 13 and 15 and are particularlypositioned as offset towards the direction counter to the transportsurface, the frames 23, 25, 51 and 51 do, when assuming the straightposition as shown in, for example, FIG. 10, tend to bend in thedirections B and B towards the transport surface.

[0149] Then, at this time, as hereinabove described, the upper edges ofthe brackets 51 and 51, which are ones of the frames, are brought incontact with the upper surfaces of the outer left and right roofingplates 23 and 25, which are the others of the frames, to thereby inhibitthe frames from being further bent in the directions B and B beyond thestraight position and, therefore, the frames 23, 25, 51 and 51 of theconveyor apparatus 3 are after all held in and locked at the straightposition.

[0150] In particular, with the conveyor apparatus according to the thirdaspect, the frames 23, 25, 51 and 51 are affected by not only theresilient restoring force of the transport belt 17 trained between andaround the rollers 13 and 15, but also a resilient restoring force ofthe timing belt 113 and do therefore tend to bend strongly in thedirection close towards the other belt run surface. Accordingly theframes 23, 25, 51 and 51, when being not bent, are firmly maintained andlocked in a non-bending condition by the roofing members 23 and 25.

[0151] Therefore, in the conveyor apparatus according to any one of thesecond and third aspects, no separate dedicated lock pin or the likeneed be employed to inhibit bending of the frames 23, 25, 51 and 51,allowing the conveyor apparatus 3 to be simplified in structure.Consequently, the number of component parts of the conveyor apparatus 3is reduced and the tare weight can also be reduced to thereby increasethe weighing accuracy. Also, the conveyor apparatus 3 can easily becleaned, resulting in increase of the cleaning capability. In addition,when the transport belt 17 is to be removed, no lock pin or the likeneed be manipulated and simply bending or straightening of the frames23, 25, 51 and 51 is sufficient, thereby simplifying the removal ormounting of the transport belt 17.

[0152] Also, when and after the conveyor apparatus 3 has been assembledin a condition ready for use, as is the case with the weighing conveyoraccording to the previously described first aspect, the rectangularsectioned end 13 c of the drive roller shaft 13 b has to be insertedinto the correspondingly rectangular hole 109 b defined in the extendedend 109 a of the second transmission shaft 109 that protrudes inwardlyfrom the downstream V-shaped arm 97 a.

[0153] Then, the engagement member 41 of the bearing unit 37 thensupporting the drive shaft 13 a opposite to the conveyor apparatus 3similarly on the downstream side is engaged in the cutout 95c defined inthe opposite V-shaped arm 95 a similarly on the downstream side. Then,as shown by C in FIG. 11, the conveyor apparatus 3 is lowered onto thesupport member 120 with the point of engagement of them used as afulcrum, until the upstream left and right engagement members 57 and 57of the conveyor apparatus 3 are engaged in the respective cutouts 95 dand 97 c in the similarly upstream V-shaped arms 95 b and 97 b. In thisway, the conveyor apparatus 3 is supported by the support member 120 tothereby complete the weight checker 1 as a whole.

[0154] Thereafter, as is the case with the weighing conveyor accordingto the previously described first aspect, when the drive motor 73 iselectrically powered on, the transport belt 17 is driven with the uppertransport surface traveling in the direction shown by the arrow A tosuccessively transport the articles X to be weighed so that the articlesX can be weighed one at a time during the transport thereof

[0155] In particular, in the conveyor apparatus according to any one ofthe second and third aspects, since the frames 23, 25, 51 and 51 are sodesigned and so configured that they cannot bend towards the side B andB of the transport surface of the transport belt 17, even though asshown by the arrow in FIG. 11, the weight of the article X to be weighedthen being transported imposes a stress on the frames 23, 25, 51 and 51to urge the latter to bend, the conveyor apparatus 3 will not bend andis rather prevented from being bend towards the opposite transportsurface (in a direction counter to the direction B) and, accordingly thepossibility of unlocking of the frames 23, 25, 51 and 51 then in thestraight position during the transport of the articles can be avoidedstably.

[0156] Also, as the drive roller 13 on the downstream side rotates, theupper belt run of the transport belt 17, which defines the transportsurface for the support of the articles, is tensioned and, accordingly,by the action of the tension, the frames 23, 25, 51 and 51 are stronglyurged to bend in the direction B and B towards the transport surface.Because of this, the conveyor apparatus 3 when held in a non-bendingstate during the use thereof, can be firmly locked at such non-bendingposition.

[0157] Also, as described in connection with the weighing conveyoraccording to the previously described first aspect, by causing thesprings 59 and 59, which are employed as the biasing members andprovided on the brackets 51 and 51, to urge the upstream driven roller15 further in the upstream direction and also by adjusting the biasingforces through a rotating manipulation of the screw rods 63 and 63, thetransport belt 17 can be assuredly held under taut at all times eventhough, for example, the material, length, resiliency and others of thetransport belt 17 varies. As a result, the resilient restoring force ofthe belt 17 can be secured and it is therefore warranted that the frames23, 25, 51 and 51 can be locked in the straight position without beingbent. Also, the tension of the belt 17 and, hence, the resilientrestoring force of the belt 17 can be adjusted and, therefore, the forceof the frames 23, 25, 51 and 51 tending the latter to bend can beadjusted variably.

[0158] Also, as described in connection with the weighing conveyoraccording to the previously first aspect, by providing on the transportbelt 17 the protruding edge portions 17 a and 17 a, which areindentations for regulating any possible displacement in position in thewidthwise direction by means of engagement with the rollers 13 and 15,any possible tortuous motion during the run of the transport belt 17 canbe suppressed, allowing the belt 17 to be stably held under taut at alltimes. As a result, the resilient restoring force of the transport belt17 can be stably secured at all times and, therefore, it is warrantedthat the frames 23, 25, 51 and 51 are locked in the straight positionwithout being bent.

[0159] Also, in the conveyor apparatus according to any one of the firstand second aspects, where the roofing members 21 . . . 21, 23 and 25 areemployed for supporting the transport surface of the transport belt 17from rear side to thereby prevent it from being slackened so that thearticles X to be weighed can be smoothly and stably transported, thoseroofing members and, more specifically, the left and right outer roofingmembers 23 and 25 are utilized to serve as stop members for avoidingbending of the frames 23, 25, 51 and 51 and, accordingly, the structureof the conveyor apparatus 3 can be simplified along with reduction ofthe number of the component parts used.

[0160] Another embodiment of the conveyor apparatus according to thesecond aspect will now be described with reference to FIGS. 12 and 13.It is to be noted that component parts identical with or similar tothose of the conveyor apparatus according to the above described secondaspect are shown by like reference numerals.

[0161] In this embodiment, as shown in FIG. 12, the support member 120is formed with hook-shaped engagement portions 120 a and 120 a. On theother hand, conveyor frames 141 and 142 of the conveyor apparatus 3 areprovided with respective pin members 141 a and 142 a.

[0162] By bending the conveyor frames 141 and 142 about the fulcrum 52,the transport belt 17 is trained between and around the rollers 13 and15. In this position, the pin members 141 a and 142 a are positioned onan upper edge portion of the support member 120 and when it is urgeddownwardly as shown by the arrow D, the pin members 141 a and 142 aslide towards a direction shown by E along the upper edge portion of thesupport member 120 and are finally received and engaged into theengagement portions 120 a and 120 a as shown in FIG. 13. In this way,the conveyor apparatus 3 is supported by the support member 120.

[0163] At this time, the conveyor frames 141 and 142 extend straight andare held in a position ready for use. The support member 120 is formedwith a cutout 120 b into which a support shaft 52 defining the bendingfulcrum is engaged and, by allowing the support shaft 52 to be broughtinto engagement with the cutout 120 b, any possible bending of theconveyor frames 141 and 142 in a reverse direction beyond the straightposition can be prevented.

[0164] Even in this embodiment, since the bending fulcrum 52 is offsetfrom the center line connecting between the rollers 13 and 15, when inthe straight position as shown in FIG. 13, forces acting in upwarddirections G and G are induced by the tension of the transport belt 17so as to act in the engagement portions 120 a and 120 a while a forceacting in a downward direction F acts on the cutout 120 b. And, in thiscondition, the conveyor apparatus 3 while being supported by the supportmember 120 is locked in the straight position.

[0165] In this way, when as shown in FIG. 13, the frames 141 and 142 ofthe conveyor apparatus 3 are not bent the pin members 141 a and 142 a ofthe conveyor apparatus 3 are engaged in the engagement portions 120 aand 120 a of the support member 120, respectively whereas when as shownin FIG. 12, the frames 141 and 142 of the conveyor apparatus 3 are bent,the pin members 141 a and 142 a of the conveyor apparatus are disengagedfrom the engagement portions 120 a and 120 a of the support member 120,respectively.

[0166] Accordingly, by causing the conveyor frames 141 and 142 to extendstraight, mounting of the transport belt 17 onto the conveyor apparatus3 and mounting of the conveyor apparatus 3 onto the support member 120or the inspecting machine can be performed simultaneously. Also, bybending the conveyor frames 141 and 142, removal of the transport belt17 from the conveyor apparatus 3 and removal of the conveyor apparatus 3from the support member 120 or the inspecting machine can be performedsimultaneously.

[0167] As a result, no extra fixture or the like dedicated to allow theconveyor apparatus 3 to be assembled together with the support member120 is needed, thereby simplifying the structure of the weighingconveyor 2. Consequently, the number of the component parts of theweighing conveyor 2 is reduced and reduction of the tare weight and,hence, increase of the weighing accuracy can be attained. Also, itbecomes easy to cleanse the weighing conveyor 2, thereby increasing thecleaning capability. In addition, when the conveyor apparatus 3 isdesired to be mounted or removed, there is no need to manipulate thefixture or the like and mere bending and straightening of the conveyorframes 141 and 142 are sufficient, allowing the selective mounting andremoval of the conveyor apparatus 3 to be simplified.

[0168] A modified form of the embodiment shown in FIGS. 12 and 13 isshown in FIG. 14. In this modified form, the upper edge portion of thesupport member 120 is formed with guide portions 120 c and 120 c definedby inclined faces that are inclined downwardly towards the engagementportions 120 a and 120 a at the opposite ends inwardly of the engagementportions 120 a and 120 a, respectively.

[0169] In this example, when the conveyor frames 141 and 142 bent aboutthe fulcrum 52 are urged towards the direction D, the pin members 141 aand 142 a are slidingly guided along the inclined faces of the guideportions 120 c and 120 c towards the engagement portions 120 a and 120 aand, therefore, the force necessary to urge towards the direction D maybe smaller than that required in the example shown in FIGS. 12 and 13.

[0170] Although in FIG. 14 reference has been made to the use of the twoguide portions 120 c and 120 c, only one of them may be sufficient.

[0171] In the next place, a further embodiment of the conveyor apparatusaccording to the third aspect will be described with reference to FIG.15. It is, however, to be noted that component parts identical with orsimilar to those in the previously described embodiment are shown bylike reference numerals.

[0172] In this embodiment, the drive motor 151 for driving the driveroller 13 is disposed between upper and lower runs of the transport belt17. An endless drive transmission belt 154 is trained between and arounda pulley 152, fixedly mounted on the drive shaft of the drive motor 151,and a pulley 153 fixedly and coaxially mounted on the drive roller 13.

[0173] At this time, the bending fulcrum 52 of the conveyor frames 141and 142 does not lie on a line of extension connecting between therespective longitudinal axes of the pulleys 152 and 153 when the frames141 and 142 are not bent, but is positioned offset downwardly therefrom.Also, the drive motor 151 is positioned on one side of the bendingfulcrum 52 adjacent the driven roller 15.

[0174] According to this design, in place of or in combination with theresilient restoring force of the transport belt 17 trained between andaround the rollers 13 and 15, and under the influence of the resilientrestoring force of the drive transmission belt 154 for transmitting thedrive of the drive motor 151 to the drive roller 13, the conveyor frames141 and 142 tend to bend towards the upper transport surface.Accordingly, so long as the conveyor frame 141 and 142 are not bent, thecondition in which they do not bend is firmly maintained and is thuslocked.

[0175] Also, when the conveyor frames 141 and 142 are bent, mounting andremoval of the transport belt 17 results in concurrent mounting andremoval of the drive transmission belt 154.

[0176] It is to be noted if in such case the transport direction is thatshown by the arrow A, as hereinbefore described the upper transportsurface of the transport belt 17 is desirably held under taut. For thispurpose, the drive motor 151 is driven in the direction b so that thedrive roller 13 can be driven in a direction shown by the arrow a.Conversely, in order for the upper run of the drive transmission belt154 to be held under taut, the drive motor 152 is driven in a directioncounter to the direction shown by the arrow b. At this time, the driveroller 13 is driven in a direction counter to the direction shown by thearrow a and the transport belt 17 runs in a direction shown by the arrowH that is counter to the direction A. In the present invention,depending on the situation, any of those directions can be suitablyselected.

[0177] In the next place, the weighing conveyor 2 according to a fifthaspect of the present invention will be described. This weighingconveyor 2 has a basic structure similar to that according to the abovedescribed first aspect and is featured in the following. Specifically, aload detector 5 for detecting the weight of the article X to be weighedthat is transported by the conveyor apparatus 3, in terms of up and downdisplacement thereof is employed, and the axis of rotation of the motor73 that is the drive source is disposed parallel to the direction ofdisplacement brought about by the article X to be weighed.

[0178] In particular, the weighing conveyor 2 according to this aspectis of a type wherein the articles X to be weighed that are placed on thetransport belt 17 are successively transported in the horizontaldirection. Accordingly, as shown in FIGS. 16 and 17, the transportsurface of the conveyor apparatus 3, that is, the upper run of thetransport belt 17 extends in the horizontal direction. Also, the rollers13 and 15 around which the transport belt 17 is trained are similarlyextend in the horizontal direction. The direction in which the transportsurface of the conveyor apparatus 3 extends is referred to as a firstdirection and is indicated by L1 shown as extending in the direction inwhich the drive roller 13 extends.

[0179] On the other hand, the load brought about by the conveyorapparatus 3 and/or the articles X to be weighed is loaded downwards onthe load cell 5 under the influence of a gravitational force.Accordingly, the elastic element 5 a of the load cell 5 displaces up anddown during detection of the load. The direction in which the elasticelement 5 a of the load cell 5 displaces during detection of the load isreferred to as a second direction and is indicated by L2 shown asextending in a direction in which the free end portion 5 c extends.

[0180] In other words, in this weighing conveyor 2, the direction L1 inwhich the transport surface of the conveyor apparatus 3 extends and thedirection L2 in which the elastic element 5 a of the load cell 5displaces lie perpendicular to each other. While in such design, thedrive shaft 73 a of the drive motor 73 for driving the conveyorapparatus 3 is rendered to extend in the same up and down direction asthe direction L2 in which the elastic element 5 a of the load cell 5displaces, not in the same horizontal direction as the direction L1 inwhich the transport surface of the conveyor apparatus 3 extends. Thedirection in which the drive shaft 73 a of the drive motor extends isreferred to as a third direction and is indicated by L3 shown asextending in a direction in which the drive shaft 73 a extends.

[0181] Thus a rotational vibration of the drive shaft 73 a of the drivemotor 73 occurs only in the horizontal direction and the directionthereof lies perpendicular to the up and down direction in which theelastic element 5 a displaces. Accordingly, the direction (horizontaldirection) in which the rotational vibration of the drive shaft 73 a ofthe drive motor 73 acts and the direction (up and down direction) inwhich the elastic element 5 a displaces during detection of the loaddoes not coincide with each other. As a result, the possibility can beavoided in which the load cell 5 picks up and detects a change in loadbrought about by the rotational vibration referred to above and, hence,the possibility of excessive external noises appearing in the weightsignal of the load cell 5 can be avoided. Therefore, reduction inweighing accuracy can be effectively avoided, resulting in increase ofthe weighing accuracy.

[0182] Moreover, since a simple design is employed in which the driveshaft 73 a of the drive motor 73 is so arranged vertically as to extendparallel to the direction in which the elastic element 5 a of the loadcell 5 displaces, the weighing conveyor 2 has a hardware structure thatdoes not become complicated. Also, since no noises is contained in theweight signal of the load cell 5, the weight signal can be used byitself and, therefore, no software structure of a signal processing isnot complicated as well.

[0183] In addition, when the drive motor 73, which is a major source ofgeneration of drive noises and is also a heavy item, is disposedadjacent the free end portion 5 c of the elastic element 5 a of the loadcell 5, the center of gravity of the drive motor 73 can be brought to aposition adjacent the center of moment of the load cell 5 and,accordingly, any influence which will be brought about by the externalnoises on the load cell 5 can be reduced. Yet, even though the drivemotor 73, which is the source of the drive noises, is positionedadjacent the free end portion 5 c, the load cell 5 will not be affectedby the influence brought about by the drive noises since the directionin which the vibration acts is different from the direction of detectionof the load cell 5.

[0184] In the meantime, since the drive shaft 73 a of the drive motor 73is so arranged as to extend in the up and down direction, the axis of arotational drive force initially generated by the drive motor 73 doesalso extend in the up and down direction. This direction does notcoincide with the horizontal direction in which the transport surface ofthe conveyor apparatus 3 extends. Yet, it does not coincide with aleftward and rightward direction in which the axis of the drive roller13, that should initially transmit the drive force, extends.

[0185] In view of the foregoing, during transmission of the power bymeans of the drive transmission mechanism 130 disposed between the drivemotor 73 and the drive roller 13, the direction in which the axis of therotational drive force generated by the drive motor 73 is so arranged asto be converted into the horizontal direction in which the transportsurface of the conveyor apparatus 3 extends and, at the same time, inthe leftward and rightward direction in which the axis of the driveroller 13 extends.

[0186] More specifically, using the pair of the bevel gears 105 and 103,a drive transmission path is bent from the direction L3, in which thedrive shaft 73 a extends, to the direction L4 in which the transmissionshaft 101 extends. In this way, the drive force of the drive motor 73can be properly and smoothly inputted to the drive roller 13 and ishence transmitted to the conveyor apparatus 3.

[0187] Hereinafter, the weighing conveyor 2 according to sixth to ninthaspects of the present invention will be described. This weighingconveyor 2 has a basic structure similar to that according to thepreviously described first aspect and is featured in the following. Inother words, respective positions of the conveyor apparatus 3 and thedrive transmission mechanism 130 relative to the load cell 5 are sochosen as to render the center of gravity R of the weighing conveyors 2,comprised of them, to approach to the center of moment S of the loadcell 5 to thereby increase the weighing accuracy.

[0188] In the weighing conveyor 2 according to the sixth aspect, theconveyor apparatus 3 is disposed above the load cell 5 which is the loaddetector and the drive motor 73, which is the drive source, is disposedat the substantially same position as the load cell 5 with respect tothe up and down direction or below the load cell 5, and the drivetransmission mechanism 130 is so disposed as to extend betweenrespective positions below and above the load cell 5. Accordingly, acomposite center of gravity R of the conveyor apparatus 3, the motor 73and the drive transmission mechanism 130 is positioned in the vicinityof the center of moment S of the load cell 5 with respect to the up anddown direction.

[0189] In the weighing conveyor according to the seventh aspect, theconveyor apparatus 3 is disposed below the load cell 5, the motor 73 isdisposed at the substantially same position as the load cell 5 withrespect to the up and down direction, and the drive transmissionmechanism 130 is so disposed as to extend between respective positionsabove and below the load cell 5, so that the composite center of gravityR of the conveyor apparatus 3, the motor 73 and the drive transmissionmechanism 130 is positioned in the vicinity of the center of moment S ofthe load cell 5 with respect to the up and down direction.

[0190] In the weighing apparatus according to the eighth aspect, theconveyor apparatus 3 is disposed at a position substantiallyintermediate of the conveyor apparatus 3 with respect to the directionof transport of the articles to be weighed, the motor 73 is disposed inthe vicinity of the load cell 5 and the drive transmission mechanism 130is so disposed as to extend between respective positions downstream andupstream of the load cell 5 with respect to the direction of transport,so that the composite center of gravity R of the conveyor apparatus 3,the motor 73 and the drive transmission mechanism 130 is positioned inthe vicinity of the center of moment S of the load cell 5 with respectto the up and down direction.

[0191] In the weighing conveyor according to the ninth aspect, theconveyor apparatus 3 is disposed at a position substantiallyintermediate of the conveyor apparatus 3 with respect to the directionof transport of the articles to be weighed, the motor 73 is disposed atthe substantially same position as the load cell 5 with respect to thetransport widthwise direction and the drive transmission mechanism 130is so disposed as to extend between the same position as the load cell 5with respect to the transport widthwise direction and right or leftposition with respect to the transport widthwise direction and also asto extend between respective positions leftwards and rightwards of theload cell 5 with respect to the transport widthwise direction, so thatthe composite center of gravity R of the conveyor apparatus 3, the motor73 and the drive transmission mechanism 130 is positioned in thevicinity of the center of moment S of the load cell 5 with respect tothe up and down direction.

[0192] The details of the weighing conveyors according to the foregoingsixth to ninth aspects, respectively, will now be described. In thefirst place, as shown in FIGS. 19 and 20, the center of gravity R of theweighing conveyor 2 is located at a position spaced a short distance L5from the center of moment S of the load cell 5 with respect to the upand down direction. Also, as shown in FIGS. 18 and 19, the center ofgravity R of the weighing conveyor 2 is located at a position spaced asmall distance L5 from the center of moment S of the load cell 5 withrespect to the direction of transport (the forward and rearwarddirection) of the articles X to be weighed. Further, as shown in FIGS.18 and 20, the center of gravity R of the weighing conveyor 2 is locatedat a position spaced a short distance L5 from the center of moment S ofthe load cell 5 with respect to the widthwise direction (leftward andrightward direction) of transport of the articles X to be weighed.

[0193] With respect to the up and down direction, as shown in FIGS. 19and 25 20, the conveyor apparatus 3 is first disposed above the loadcell 5 and the drive motor 73 is arranged at a position substantiallylevel with the load cell 5.

[0194] Accordingly, according to this, the center of gravity R of theweighing conveyor 2 would be excessively spaced upwardly from the centerof moment S of the load cell 5. In view of this, the drive shaft 73a ofthe drive motor 73 is arranged so as to extend downwardly and the drivetransmission mechanism 130 (and the support member 120), which isanother heavy item, is disposed so as to extend from a position belowthe load cell 5 towards the conveyor apparatus 3 thereabove. In otherwords, the drive transmission mechanism 130 and the support member 120are also positioned at a location below the load cell 5. By this design,a bias of the center of gravity R of the weighing conveyor 2 isrectified, that is, the center of gravity R is lowered, towards aposition approaching the center of moment S of the load cell 5.

[0195] In contrast thereto, if at this time the drive transmissionmechanism 130 is so arranged as to extend upwardly from the positionabove the load cell 5 or as to extend upwardly from the positionsubstantially level with the load cell 5, the bias of the center ofgravity R of the weighing conveyor 2 will not be rectified and, rather,the center of gravity R will undesirably be displaced having been biasedfurther upwardly.

[0196] It is to be noted that, for example, the drive motor 73 may bepositioned beforehand at a location below the load cell 5.

[0197] With respect to the transport direction (the forward and rearwarddirection), as shown in FIGS. 18 and 19, the load cell 5 is firstarranged at a location substantially intermediate of the conveyorapparatus 3 with respect to the transport direction and the drive motor73 is arranged upstream of the load cell 5 with respect to the transportdirection. Accordingly, according to this, the center of gravity R ofthe weighing conveyor 2 is excessively spaced in a direction upstream ofthe center of moment S with respect to the transport direction. In viewof this, the drive roller 13 is arranged at a location downstream withrespect to the transport direction and the drive transmission mechanism130 (and the support member 120), which is another heavy item, isarranged so as to extend from the position upstream of the load cell 5towards the drive roller 13 on the downstream side. By this design, abias of the center of gravity R of the weighing conveyor 2 is rectified,that is, the center of gravity R is shifted in a direction downstream ofthe transport direction, approaching the center of moment S of the loadcell 5.

[0198] In contrast thereto, if at this time the drive roller 13 is soarranged as to occupy a position upstream with respect to the transportdirection and the drive transmission mechanism 130 is arranged so as toextend only in a region upstream of the load cell 5, the bias of thecenter of gravity R of the weighing conveyor 2 will not be rectifiedand, rather, the center of gravity R will undesirably be displacedhaving been biased in the upstream direction.

[0199] It is to be noted that if the drive motor 73 is arranged, forexample, downstream of the load cell 5 beforehand with respect to thetransport direction, the drive roller 13 is to be arranged upstream ofthe transport direction and the drive transmission mechanism 130 is tobe so arranged as to extend from the position downstream of the loadcell 5 towards the position upstream thereof.

[0200] With respect to the transport widthwise direction (leftward andrightward direction), as shown in FIGS. 18 and 20, the load cell 5 is atfirst disposed at a location substantially intermediate of the conveyorapparatus 3 with respect to the transport widthwise direction and thedrive motor 73 was disposed at the substantially same position as theload cell 5. Accordingly, in this condition, the center of gravity R ofthe weighing conveyor 2 coincides with the center of moment S of theload cell 5 in the transport widthwise direction.

[0201] However, the drive transmission mechanism 130 (and the supportmember 120), which is another heavy item, has to be disposed between thedrive motor 73 and the conveyor apparatus 3 and it can be consideredthat, at that time, the center of gravity R of the weighing conveyor 2will displace from the center of moment S of the load cell 5 leftwardsor rightwards of the transport widthwise direction.

[0202] However, since as compared with the weight of the drivetransmission mechanism 130 the weight of the conveyor apparatus 3 andthe weight of the drive motor 73 is far heavier, even though the drivetransmission mechanism 130 is so disposed as having been displacedeither leftwards or rightwards of the transport widthwise direction, theextent to which the center of gravity R of the weighing conveyor 2displaces from the center of moment S of the load cell 5 will not becomeso large. Accordingly, the drive transmission mechanism 130 is disposedso as to extend from the position substantially level with the load cell5 in the transport widthwise direction in a direction leftwards orrightwards of the transport widthwise direction. It is to be noted thatat this time the extend to which the center of gravity R of the weighingconveyor 2 is shifted in the transport widthwise direction can besuppressed even in the presence of the support member 120 that issubstantially symmetric with respect to the leftward and rightwarddirection.

[0203] Nevertheless, although the use of the two drive transmissionmechanisms 130 arranged in symmetric relation to each other with respectto the leftward and rightward direction is preferred, it may occur thatthe use of the two drive transmission mechanisms would result incomplicated rotation of the drive roller 13. Also, the tare weight Wqwould increase, and it is no therefore undesirable in terms of theweighing accuracy.

[0204] It is to be noted that the drive motor 73 may be arranged, forexample, leftwards or rightwards of the load cell 5 beforehand withrespect to the transport widthwise direction. In such case, the drivetransmission mechanism 130 has to be arranged so as to extend leftwardsand rightwards of the transport widthwise direction with the load cell 5positioned intermediate thereof. In other words, when the drive motor 73is arranged leftwards of the load cell 5, the drive transmissionmechanism 130 has to be arranged so as to extend from left to right. Atthis time, the drive transmitting timing belt 113 and others arearranged rightwards of the conveyor apparatus 3. Conversely, when thedrive motor 73 is arranged rightwards of the load cell 5, the drivetransmission mechanism 130 has to be arranged so as to extend fromrightwards to leftwards of the load cell 5. At this time the drivetransmitting timing belt 113 and others are arranged leftwards of theconveyor apparatus 3.

[0205] As discussed hereinabove, since the center of gravity R of theweighing conveyor 2 is spaced a small distance L5 from the center ofmoment S of the load cell 5 in three dimensions in the up and downdirection, the forward and rearward direction and the leftward andrightward direction, the force of moment acting on the load cell 5 canbe suppressed to a minimal value. Accordingly, a frequency region of thenoise component to be removed that would be generated because of theforce of moment can increase enough to allow a low pass filter toperform a filtering process in a reduced time, thereby enabling theweighing operation to speed up and, therefore, the weighing accuracy canbe increased.

[0206] Moreover, in such case, by tailoring arrangement of the conveyorapparatus 3, the drive motor 73 and the drive transmission mechanism 130relative to the load cell 5, the center of gravity R of the weighingconveyor 2 so constructed with those components is brought to thelocation in the close vicinity of the center of moment S of the loadcell 5 and, because the center of gravity R of the weighing conveyor 2is thus brought to the location in the close vicinity of the center ofmoment S, and not because the conveyor apparatus 3 is designed to havean increased size with the load cell 5 and the drive motor 73 and thedrive transmission mechanism 130 accommodated therein, the weight of theconveyor apparatus 3 and, thus, the tare weight Wq of the conveyorapparatus 3 does not increase.

[0207] Accordingly, it is possible to minimize both the tare weight Wqand the center-to-center distance L5 and the force of moment acting onthe load cell 5 can be effectively and assuredly suppressed down to aminimum value. Therefore, the frequency region of the noise componentincreases assuredly, the filtering time required for the low pass filterto perform its filtering process is reduced assuredly, and the weighingoperation can be speeded up. Also, the weighing accuracy can beincreased.

[0208] It is to be noted that although in this embodiment the conveyorapparatus 3 has been arranged above the load cell 5, the conveyorapparatus 3 may be arranged below the load cell 5 as shown in FIG. 21 (asuspended structure). In such case, as shown therein, the drive shaft 73a of the drive motor 73 is arranged, for example, so as to extendupwardly and the drive transmission mechanism 130 and the support member120 are arranged, for example, so as to extend from a position above theload cell 5 towards the conveyor apparatus 3 positioned below the loadcell 5. In other words, in a manner reverse to that describedpreviously, the drive transmission mechanism 130 and a portion of thesupport member 120 are allowed to exist concurrently at the positionabove the load cell 5. By this design, the center of gravity R of theweighing conveyor 2 is pulled upwardly to approach the center of momentS of the load cell 5.

[0209] It is to be noted that, in such case, the drive motor 73 ispositioned in the vicinity of the load cell 5 with respect to the up anddown direction. In other words, for example, the drive motor 73 isdisposed at the substantially same position as the load cell 5 withrespect to the up and down direction or above the load cell 5.

[0210] It is also to be noted that although in any of the foregoingembodiments the load cell 5 has been employed as the load detector, thepresent invention may not be always limited thereto and the loaddetector of, for example, an electromagnetically balanced type may beemployed. In other words, any load detector of a structure wherein oneof the opposite end is rendered to be the fixed end while the other ofthe opposite ends is rendered to be the free end and the load is adaptedto be loaded on the free end so that the load can be detected in termsof up and down displacement of the load in the free end can be employedin the practice of the present invention.

[0211] Although the present invention has been fully described inconnection with the preferred embodiments thereof with reference to theaccompanying drawings which are used only for the purpose ofillustration, those skilled in the art will readily conceive numerouschanges and modifications within the framework of obviousness upon thereading of the specification herein presented of the present invention.Accordingly, such changes and modifications are, unless they depart fromthe scope of the present invention as delivered from the claims annexedhereto, to be construed as included therein.

What is claimed is:
 1. A weighing conveyor, which comprises a conveyorapparatus for successively transporting articles to be weighed, a loaddetector for detecting a weight of the articles to be weighed that aresuccessively transported by the conveyor apparatus, and a housing foraccommodating the load detector, wherein a fixed end of the loaddetector is connected with the housing and a free end thereof isconnected with a support member for supporting the conveyor apparatus,said support member protruding outwardly from a bottom surface of thehousing.
 2. The weighing conveyor as claimed in claim 1, wherein theconveyor apparatus is arranged immediately above the housing and thesupporting member after having protruded outwardly from the bottomsurface of the housing extends upwardly of the housing towards theconveyor apparatus.
 3. The weighing conveyor as claimed in claim 1,wherein a surface of the housing confronting the conveyor apparatus isdefined by a downwardly continuously inclined face.
 4. The weighingconveyor as claimed in claim 1, further comprising a drive source fordriving the conveyor apparatus, said drive source being accommodatedwithin the housing.
 5. The weighing conveyor as claimed in claim 4,further comprising a drive transmission mechanism for transmitting adriving force of the drive source to the conveyor apparatus isaccommodated within the support member.
 6. A conveyor apparatus, whereinwhen a frame structure is bent, an endless transport belt can be mountedon or removed from at least one pair of rollers supported by the framestructure, wherein a bending fulcrum of the frame structure lies at alocation on one side of a line of extension, connecting respective axesof rotation of the rollers together when the frame structure is notbent, adjacent one of runs of the transport belt, and wherein there isprovided a stop member for inhibiting the frame structure from beingbent towards the other of the runs of the transport belt.
 7. Theconveyor apparatus as claimed in claim 6, wherein the other of the runsof the transport belt is a transport surface for the articles to beweighed.
 8. The conveyor apparatus as claimed in claim 6, wherein therollers are rotatable to allow the other of the runs of the transportbelt to be held under tension.
 9. The conveyor apparatus as claimed inclaim 6, wherein there is further provided a biasing member for biasingat least one of the rollers in a direction required for a distancebetween the rollers to increase.
 10. The conveyor apparatus as claimedin claim 6, wherein the transport belt is provided with indentationsengageable with the rollers to regulate displacement in position in adirection widthwise thereof.
 11. The conveyor apparatus as claimed inclaim 6, wherein the frame structure is provided with roofing member forsupporting the run of the transport belt from backside thereof andwherein the stop member is defined by the roofing members.
 12. Aconveyor apparatus of a type wherein when a frame structure is bent, anendless transport belt can be mounted on or removed from at least onepair of rollers supported by the frame structure, said conveyorapparatus comprising a drive source for driving one of the rollers; apulley mounted on a drive shaft of the drive source; a pulley mountedcoaxial with one of the rollers; an endless drive transmitting belttrained between and around the pulleys, wherein a bending fulcrum of theframe structure lies at a location on one side of a line of extension ofrespective axes of rotation of the pulleys, when the frame structure isnot bent, adjacent one of runs of the drive transmitting belt; and astop member for inhibiting the frame structure from being bent towardsthe other of the runs of the drive transmitting belt.
 13. An articleinspecting machine equipped with a conveyor apparatus as defined inclaim 6 for transporting articles to be inspected successively.
 14. Anarticle inspecting machine equipped with a conveyor apparatus as definedin claim 7 for transporting articles to be inspected successively. 15.The article inspecting machine as claimed in claim 13, wherein there isprovided an engagement for supporting a conveyor apparatus when engagedwith the conveyor apparatus, and wherein the conveyor apparatus and theengagement are engaged with each other when a frame structure of theconveyor apparatus is not bent, but are disengaged from each other whenthe frame structure of the conveyor apparatus is bent.
 16. A weighingconveyor for weighing a weight of an article to be weighed while thearticle to be weighed is transported, said weighing conveyor comprisinga conveyor apparatus for transporting the article to be weighed andhaving a transport surface laid horizontally; a drive source for drivingthe conveyor apparatus, and a load detector for supporting the conveyorapparatus and the drive source and for detecting the weight of thearticle to be weighed that is supported and transported by the conveyorapparatus, in terms of up and down displacement thereof, an axis ofrotation of the drive source being arranged parallel to a direction ofsuch displacement.
 17. The weighing conveyor as claimed in claim 16,wherein the drive source is arranged on a free end of the load detector.18. The weighing conveyor as claimed in claim 16, further comprising adrive transmission mechanism for transmitting a driving force of thedrive source to the conveyor apparatus, wherein an axis of a rotatorydrive force generated by the drive source is converted into a directionparallel to the transport surface by the drive transmission mechanism.19. A weighing apparatus equipped with a weighing conveyor as defined inclaim
 16. 20. A weighing conveyor for weighing a weight of an article tobe weighed while the article to be weighed is transported, said weighingconveyor comprising a conveyor apparatus for transporting the article tobe weighed; a drive source for driving the conveyor apparatus; a drivetransmitting mechanism for transmitting a drive force of the drivesource to the conveyor apparatus; and a load detector for supporting theconveyor apparatus, the drive source and the drive transmittingmechanism and for detecting the weight of the article to be weighed thatis supported and transported by the conveyor apparatus, wherein theconveyor apparatus is disposed above the load detector, the drive sourceis disposed at a location substantially level with the load detector, orbelow the load detector, with respect to an up and down direction, andthe drive transmission mechanism is disposed so as to extend between aposition below the load detector and a position above the load detectorwith the load detector intervening therebetween, such that a compositecenter of gravity of the conveyor apparatus, the drive source and thedrive transmission mechanism is brought to a position in a vicinity of acenter of moment of the load detector in the up and down direction. 21.A weighing conveyor for weighing a weight of an article to be weighedwhile the article to be weighed is transported, said weighing conveyorcomprising a conveyor apparatus for transporting the article to beweighed; a drive source for driving the conveyor apparatus; a drivetransmitting mechanism for transmitting a drive force of the drivesource to the conveyor apparatus; and a load detector for supporting theconveyor apparatus, the drive source and the drive transmittingmechanism and for detecting the weight of the article to be weighed thatis supported and transported by the conveyor apparatus, wherein theconveyor apparatus is disposed below the load detector, the drive sourceis disposed at a location substantially level with the load detectorwith respect to an up and down direction, and the drive transmissionmechanism is disposed so as to extend between a position below the loaddetector and a position above the load detector with the load detectorintervening therebetween, such that a composite center of gravity of theconveyor apparatus, the drive source and the drive transmissionmechanism is brought to a position in a vicinity of a center of momentof the load detector in the up and down direction.
 22. A weighingconveyor for weighing a weight of an article to be weighed while thearticle to be weighed is transported, said weighing conveyor comprisinga conveyor apparatus for transporting the article to be weighed; a drivesource for driving the conveyor apparatus; a drive transmittingmechanism for transmitting a drive force of the drive source to theconveyor apparatus; and a load detector for supporting the conveyorapparatus, the drive source and the drive transmitting mechanism and fordetecting the weight of the article to be weighed that is supported andtransported by the conveyor apparatus, wherein the load detector isarranged at a location substantially intermediate of the conveyorapparatus with respect to a direction of transport of the article to beweighed, the drive source is arranged adjacent the load detector and thedrive transmission mechanism is arranged so as to extend between aposition downstream of the direction of transport and a positionupstream of the direction of transport with the load detectorintervening therebetween, such that a composite center of gravity of theconveyor apparatus, the drive source and the drive transmissionmechanism is brought to a position in a vicinity of a center of momentof the load detector in the transport direction.
 23. A weighing conveyorfor weighing a weight of an article to be weighed while the article tobe weighed is transported, said weighing conveyor comprising a conveyorapparatus for transporting the article to be weighed; a drive source fordriving the conveyor apparatus; a drive transmitting mechanism fortransmitting a drive force of the drive source to the conveyorapparatus; and a load detector for supporting the conveyor apparatus,the drive source and the drive transmitting mechanism and for detectingthe weight of the article to be weighed that is supported andtransported by the conveyor apparatus, wherein the load detector isarranged substantially intermediate of the conveyor apparatus withrespect to a transport widthwise direction of the article to be weighed,the drive source is arranged at a location substantially level with theload detector with respect to the transport widthwise direction, and thedrive transmission mechanism is arranged so as to extend between aposition substantially level with the load detector and a positionleftwards or rightwards of the transport widthwise direction, or so asto extend between respective positions leftwards and rightwards of thetransport widthwise direction with the load detector interveningtherebetween, such that a composite center of gravity of the conveyorapparatus, the drive source and the drive transmission mechanism isbrought to a position in a vicinity of a center of moment of the loaddetector in the transport widthwise direction.
 24. The weighing conveyoras claimed in claim 20, wherein the load detector is arrangedsubstantially intermediate of the conveyor apparatus with respect to thedirection of transport of the article to be weighed, the drive source ispositioned adjacent the load detector, and the drive transmissionmechanism is arranged so as to extend between respective positionsupstream and downstream of the direction of transport with the loaddetector intervening therebetween, such that the composite center ofgravity of the conveyor apparatus, the drive source and the drivetransmission mechanism is brought to the position in the vicinity of thecenter of moment of the load detector also in the direction oftransport.
 25. The weighing conveyor as claimed in claim 20, wherein theload detector is arranged substantially intermediate of the conveyorapparatus with respect to the transport widthwise direction, the drivesource is positioned at a location substantially level with the loaddetector with respect to the transport widthwise direction, and thedrive transmission mechanism is arranged so as to extend between alocation substantially level with the load detector with respect to thetransport widthwise direction and a location leftward or rightward ofthe transport widthwise direction, or so as to extend between respectivelocations leftwards and rightwards of the transport widthwise directionwith the load detector intervening therebetween, such that the compositecenter of gravity of the conveyor apparatus, the drive source and thedrive transmission mechanism is brought to the position in the vicinityof the center of moment of the load detector also in the transportwidthwise direction.
 26. A weighing apparatus equipped with a weighingconveyor as defined in claim 20.